Pump



April 1942- B. F. SCHMIDT 2,273,498

PUMP

- Filed Oct. 22, 19 57 5 -S eet 1 i ii. 6'9 67 1262.2. 6'7 62 6'2 VA 2067 J" 4v y 46;, -46' 7 59 6'0 50 y E a? i 5 Sheets-Sheet 2 B. F. SCHMIDTPUMP Filed Oct. 22, 1957 April 14,

;yamz'n 11906712121 1;

April 1942- B. F.YSICHMIDT 2,279,498

PUMP

Filed Oct. 22, 1957 5 Sheets-Sheet 3 3mm Sc'kmidi.

April 14, 1942.

B. F. SCHMIDT .PUMP

Filed Oct. 22, 1937 5 Sheets-Sheet 5 Benjamin J? Schmidt:

Patented Apr. 14, 1942 UNITED STATES "PATENT OFFICE PUMP Benjamin F.Schmidt, Los Angeles, Calif.

Application October 22, 1937, Serial No. 170,408 3 Claims. (01. 103-165)This invention relates to a pump and more particularly pertains to adouble acting submersible fluid piston pump of the type shown in myco-pending application Ser. No. 166,097 which type of pump is especiallyapplicable for use in pumping liquids from deep wells and particularlyin oil well-pumping operations.

An object of the invention is to provide a pump embodying a body offluid of greater specific gravity than the liquid to be pumped, andinsoluble therein, herein referred to as pumping fluid, such fluid beingconfined within the pump housing in association with a reciprocal pistonin such fashion that the level of the fluid will rise and fall onreciprocation of the piston and thereby be caused to effect a pumpingaction with the aid of the customary valve arrangement to effect intakeof liquid to be pumped into the pump on the fall of the fluid level inthe pump, and to effect elevation of the liquid within the pump onraising of the fluid level.

While the pumping fluid may comprise any suitable liquid, mercury hasbeen found to be admirably suited for the purpose and it may be usedalone or in conjunction with some other fluid having the requisitecharacteristics.

A particular object of the invention is to provide an eiiectiveautomatic means for maintaining the working level of the pumping fluidconstant irrespective of seepage thereof in either direction past itsactuating piston, and whereby the level of the fluid may be maintainedat such height within the pump as to prevent the oil or liquid beingpumped from coming in contact with "andaccordingly the invention is notto be limited to the double acting system.

With the foregoing objects in View, together with such other objects andadvantages as may I subsequently appear, the invention is carried intoeiiect as illustrated by way of example in the accompanying drawings inwhich: r Fig. 1 is a view in vertical section taken 0 the line l-l ofFig. 9 showing a portion of the pump containing the pumping mechanismand showing the manner in which the pair of pumpmg fluid columns areactuated alternately by the reciprocation of a single piston to effect adouble acting pumping action;

Fig. 2 is a detail in horizontal section taken on the line 2-2 of Fig.1;

the pump piston and piston red at points where those parts are subjectto wear, thus efiectively protecting the pump packing and piston ringsagainst excessive wear occasioned by the presence of sand or grit in theliquid being pumped.

Another object is to provide a pump of the above character which isrendered double acting.

by the employment of a pair of pumping fluid columns arranged to beactuated by a single reciprocal piston in such manner that one of thecolumns will act to discharge liquid from the pump on the upstroke ofthe piston while the other column will act to discharge liquid from thepump on the downstroke of the piston.

A furtherobject is to provide a float controlled valve arrangementaffording a communication between the pairs of columns of pumping fluidacting to automatically maintain substantially corresponding ranges oftravel of the working surfaces of the fluid columns under the displacement action of the reciprocal piston.

While the invention is generally directed to a double acting pumpcertain features thereof are applicable to single acting fluid systempumps Fig. 3 is a detail in horizontal section taken on the line 3--3 ofFig. 1;

Fig. 3a is a detail in vertical section taken on the line 3a 3a of Fig.1 showing the equalizing valve in its .open position.

Fig. 4V is a detail in horizontal section taken on the line 44 of Fi 1;

Fig. 5 is a view in vertical section taken on the line 55 of Fig. 9showing a portion of the pump connecting with the upper end of the pumpsection shown in Fig. 1 and showing the manner of effecting a sealaround'a vertically reciprocal sucker rod, where such rod is employed,in operating the pump piston from a point remote from the pump;

Fig. 6 is a detail in horizontal section taken on the line 5-6 of Fig.5;

Fig. 7 is a detail in horizontal section taken on the line |-'l of Fig.5; I

Fig. 8 is a detail in horizontal section taken on the line 8-8 of Fig.5;

Fig.9 is a view in elevation with portions broken away of the assembledpump sections of a modified form of the pump structure showing the pumpas adapted to effect discharge through a pipe line connecting with thepump housing;

Fig. 11 is a sectional plan view taken on the line H-H of Fig. 10;

Fig. 12 isa detail in section as seen on the line l2--!2 of Fig. 10;

Fig. 13 is a view in vertical section partly in elevation of a modifiedform of the pumping mechanism in which the pumping fluidis shown ascomprising mercury in association with a liquid insoluble in the liquidbeing pumped, and in which pumping fluid the pump piston'works.

Fig. 14 is a view in cross section taken on the line l4l4 of Fig. 13; V

Fig. 15 is a view in cross section taken on th Fig. 16 is a fragmentaryinverted plan view as seen'on the line |6|6 of Fig. 13;

Fig. 17 is a view in vertical section with parts in elevation of amodified form of the pumping mechanism shown in Fig. 13;

Fig. 18 is a detail in section as seen on the line |9-|8 of Fig. 1'7;

Fig. 19 is a diagram in vertical section depicting a feature of theinvention as applied to a single acting fluid piston pump;

Fig. 20 is a detail in horizontal section taken on the line 29--29 ofFig. 19.

Referring to the drawings more specifically A indicates generally asection of the pump embodying the pumping-mechanism and which section asparticularly shownin Figs. 1 to 4 inclusive, embodies a housingcomprising upper and lower lengths of tubing 26 and 2| respectivelywhich are threaded on and project in axial alignment from opposite sidesof a septum 22. The upper end of the upper tubing section29 is fittedwith a cap 23, and closing and threaded on the lowerendof the lowertubing section 2| is a coupling block 24.

' Extending axially'through the cap 23 is a cylinder 25 which passesthrough the septum 22 and connects at its lower end with a tubular shoe26 which seats on the block 24 and which cylinder25 is fitted with apiston 27 afiixed to a sucker rod 28 leading upwardly through thecylinder and passing througha packing gland 29 carried on the cap 23;the sucker rod being adapted to be reciprocated'longitudinally to effectreciprocation of the piston 21.

' The space between the septum 22 and the shaft 23 is divided into twolongitudinally extending compartments B and C by partitions 39 asparticularly shown in Fig. 2, which partitions extend radially betweenthe outer periphery of the cylinder 25 and the inner periphery of thetubing section 20, and extend vertically between the septum 22 and thecap 23. The compartment B is in communication with the lower end of thecylinder 25 through a tube 3| which extends downwardly from a passage 32leading through the septum 22 from compartment B; the tube 3| connectingwith the passage 33 of the tubular shoe which passage 33 opens to thecylinder 25 below the piston 21. I

Leading from the cylinder '25 above the piston 21 is a passage 34 formedin and extending upwardly through the septum 22 and opening to thecompartment 0.. Mounted in the passages 33 and 34 for verticalreciprocal movement are tubular slide valves 35 and 36 normally held intheir lowermost seated positions by expansion springs 31 bearing betweenthe upper ends of the valves 35. and 36 and apertured plugs 38 screwedin the upper ends of the passages 33 and 34. The valve 35 normallycloses a port 39 at one end of a passage 49 formed in the septum 22 andopening upwardly into the compartment C. The valve 36 normally closesa-port 4| at one end of a passage 42 formed in the septum and openingto. the compartment B.

The valves 35 and 36 are formed at their upper ends with normally openpassages 43 through which loosely extend vertical stems 44 slidablysupported in guides 45 carried by the cylinder 25. The stems are fittedat their upper ends with floats 46. The lower ends of the stems 44 arefitted with ball valves 41 which are adapted to be moved upwardly underthe urge of the floats 46 to efiect closing of the passages 43.

The compartments B and C are partly filled passage 34.

with columns D and E of mercury in which the floats 45 are buoyantlysupported. The mercury column D in compartment B leads to the lower endof the piston 21 through the valve 35, tube 3| and passage 33. Themercury column E in the compartment C extends into the cylinder 25 abovethe piston 21 through the valve 36 and A mercury column F is formedwithin the cylinder 25 above the passage 34 into which projects a tube48 leading downwardly from the packing gland 29 and loosely encirclingthe sucker rod 29. The surfaces of the parts contacted by the mercuryare silvered.

The block 24 at the lower end of the section A is fitted with intakepassages 50 connectingwith an intake pipe 5| fitted with a foot valve52; the passages 5|) opening to a chamber G extending between the block24 and the septum 22. Formed in the septum 22. are passages 53 and 54which lead upwardly therethrough and connectwith vertically extendingtubes 55 and 56 leading upwardly through the mercury columns D and E inthe compartments B and C and terminating above the maximum level of thesurfaces of the mercury columns. The upper end of each of the tubes 55and 56 is fitted with an upwardly opening ball check valve 51 arrangedin a cage 58. The passages 53 and 54 and the tubes 55 and 56 afiordcommunications between the chamber G below the septum 22 and the upperportions of the chambers B and C extending above the mercury columns Dand E.

The cap 23 at the upper end of section A is formed with a pair ofdischarge passages 59 and 60 leading from the chambers B and Crespectively, each of which passages is fitted with an upwardly openingball check valve 5|. The upper ends of the passages 59 and 66 above thevalve 6| may be in open communication through ports 62 with the interiorof a tube H in which the housing A is mounted as shown in Fig. 9, andwhich tube H leads upwardly in a well bore to any suitable point ofdischarge, or the ports 62 may be connected with a separate pipe line asshown in Fig. 10 as will be later described.

Where the sucker rod 28 is reciprocated from a point remote from thepump housing it is necessary to anchor the latter in the casing H. Ashere shown in Fig. 9 this is accomplished by extending the intake pipe5| downwardly through a reduction coupling 63 on the lower end of thecasing H and through a reduced length of tubing '64 connected with thecoupling 63, and fitting the lower end of the intake tube with astandard pump fitting 65 adapted to be latched into engagement with thereduced end portion of the pump intake in a conventional manner.

Where the sucker rod 28 is to be reciprocated from above and remote fromthe housing A, means are provided for affording a seal for the suckerrod above the packing gland 29, so as to efi'ectively prevent sand orgrit contained in the liquid being pumped from entering the gland. Thismeans as particularly shown in Figs. 5 to 9 inclusive embodies a housingJ including a cylindrical jacket 66 fitted at one end with a couplingblock 61 having a base flange 61' which flange is formed with the outletopenings 62 and which is detachably connected to the cap 23 of the pumpsection A by bolts 61". The other end of the jacket 66 is fitted with acap 68. The coupling block 61 and cap 68 are formed respectively withaxially aligned openings 69 and 69' through which the sucker rod 28extends and leads upazraeoe wardly to any suitable reciprocatingmechanism not necessary to be here shown.

Carried on the coupling block 61 interiorly of is arranged in the spacebetween the tubes 10 and II, and extending into the mercury column Lintermediate the tubes 10 and H in concentric relation thereto is a tube13 which is open at its lower end and which extends upwardly around thesucker rod 28 and connects with a collar 14 fastened to the rod as byscrews 15; the collar 14 being spaced relative to the upper ends of thetubes 16 and H and to the cap '68 to permit the requisite pumping strokeof the sucker rod. The collar 14 is formed with a tubular extension 15which leads upwardly around the sucker rod" in close contact therewithand passes through the opening 69' in spaced relation to the walls ofthe latter to permit ingress of the liquid being pumped freely into theupper end of the housing J. The upper end of the extension 16 is fittedwith a packing gland 11 to effectively seal the joint around the suckerrod.

thereof with a series of opening 18 to permit the escape of sand orother solids settling out of the liquid contained in the jacket 66.

In the construction of the pumping mechanism depicted in Fig. 1 andpreviously described, the pump piston 21 is set forth as operatingdirectly in a body of mercury. The invention, however, is subject tomodification in this respect by a construction and arrangement wherebywhile utilizing a pair of mercury columns as fluid pistons such columnsmay be acted on by another liquid insoluble in the liquid being pumpedand in which such other liquid the pump piston works. A form of thismodified construction is illustrated in Figs. 13 to 16 inclusive inwhich Y indicates generally the pump housing which embodies upper andlower tubular section's I56 and I5I respectively, which sections arescrewed together at their adjacent ends. fitted with a cap I52 formedwith discharge openings I53 and the lower end of the lower section I5Iis fitted with a coupling I54 connecting with an intake pipe I55 andfitted with a foot valve I56 arranged in a passage I51. The lowersection I5I is formed intermediate its end with a septum I58 from theopposite sides of which extend diametrical partitions I59 and I60leading to end walls I6I and I62 closing the upper and lower endsrespectively of the section I5I; the partition I59 dividing the upperportion of the section I5I into a pair of chambers I63 and I64 and thepartition I 60 dividing the lower-portion of the section I5I into a pairof chambers I65 and I66.

The upper section I50 is The jacket 66 is formed adjacent the lower endLeading upwardly into the chambers I65 and I I66 is a pair of tubes I61and I68 the lower ends of which open to the passage I 51 through the endthe chambers I65 and I66 and have their upper ends extending throughpacking glands I13 and I14 in'the end wall I6I;' the upper ends of thetubes HI and I12 opening to the interiorof the upper section I56 of thepump housing but being normally closed by ball valves I15 and I16.

Leading downwardly from the septum I58 into the chambers I65 and I66 aretubes I11 and I19, the upper ends of which open to the chambers I63 andI64 at the'upper face of the septumand the lower ends of which open tothe chambers I65 and I66 adjacent to but spaced from the end wall I62.The tubes I11 and I18 are fitted at their lower ends with floatcontrolled valve I19 and I89 which are in the form of balls and arebeing pumped.

Arranged in the upper pump section I56 is a cylinder I90 the lower endof which is connected to the end wall I5I and the upper end of whichfastens to the cap I52; the cylinder I96 being fitted with a piston I9Icarried on a vertically reciprocal sucker rod I92. The lower end of thecylinder I90 communicates with thechamber I63 through a conduit I93which leadsfrom the lower end portion of the cylinder downwardly throughthe partition I6I and opens to the chamber I63. The upper portion of thecylinder I99 above the pistonISI is in open communication with thechamber I66 througha conduit I94 which opens at its upper end totheinterior of the cylinder I96 and'has its lower end extending through thepar 'tion I6I and opening to the chamber I64.

Arranged in the space extending between the level of the mercury columnI85 through the upper portion of the chamber I63, conduit I93 and lowerportion of the cylinder I 96 below the piston I9I, is a body of liquidI95, and occupying the space above the mercury column I86 in the chamberI64 and extending through the conduit I94 into the upper portion of thecylinder I9il-above the piston I9I is a body of liquid I96. The liquidbodies I95 and I96 are composed of liquids of specific gravitiesexceeding that of the liquids being pumped and also insoluble in thelatter; It

will be manifest that in the construction just described the piston HIIwill work in the liquid bodies 595 and I96 and in effecting displacementthereof will displace the mercury columns I85 and I86 without coming incontact therewith.

In the construction shown in Fig. 17, which constitutes a modified formof the construction shown in Fig. 13, corresponding reference characters designatecorresponding parts in the two views. In this instancethe upper end portions of the tubes I11 and I18 extend into the chambersI63 and I65 a short distance above the septum I58 and slidably mountedon the protruding end portion of each of the tubes I11 and I19 is asleeve I91 fittedwith a valve seat 96 and a fioat' controlled valve I99which latter is in the form of a ball and is carried on an upwardlyextending stem 2% fitted at its upper end with a float EDI asparticularly shown in Fig. 18. The

sleeve H1 is normally maintained in an elevated "position under the urgeof a spring 292 bearing between the septum I58 and the flange 203 on thesleeve I91.

Mounted in the partition I59 is a valve block 204 the opposed ends ofwhich protrude into the chambers I63 and I64 above the sleeve I91, andformed in the valve block 204 is a pair of passages 205 and 206 openingat their ends to the chambers I63 and I64. Mounted on the block 204 is avertically reciprocal slide valve 201 controlling the passage 205; thevalve 201 having a port 208 arranged to be positioned in and out ofregister with the passage 295. The lower end of the valve 201 isconnected by a rod 209 to the sleeve I91 on the tube I11.

Mounted in the portion of the valve block 204 extending into the chamberI64 is a slide valve ZID for controlling the passage 206; the valve 2I0havinga port 2II arranged to be moved in and out of register with thepassage 206 on vertical reciprocal movement of the valve 2 I whichlatter is connected by a rod 2I2 with the sleeve I91 car ried by thetube I18.

The passages 205 and; 206 open to the chambers I63 and I64 above thelevels of the mercury columns I85 and I86 in the chambers and serve 7when opened to afford a communication between the liquid columns I95 andI96 contained in the chambers I63 and I64 above the mercury columns I85and I86 on opening of either of the valves 201 or 2I0, so that transferof liquid from the column I95 may be made to the liquid in the columnI96, or vice versa, as may be required in order to maintain anapproximate balance of the bodies of such liquidson opposite sides ofthe piston I9I in compensation of' leakage of the liquids past thepistons.

The feature of the invention of operating the piston apart from a bodyof mercury is applicable to other forms of mercury piston pumps thanabove described. As an example, the application of this feature to asingle acting mercury piston pump is illustrated in Figs. 19 and 20, inwhich Z indicates a pump cylinder having an upper end wall 2I3 formedwith a discharge outlet 2I4; the cylinder also having a lower end wall2I5 from which upwardly extends an intake tube 2 I 6 fitted at its upperend with a ball check valve 2I1. A septum 2I8 is provided intermediatethe ends of the cylinder Z from the under side of which extends adiametrical partition 2I9 leading to the end wall 2I5 and dividing thesleeve below the septum 2I8 into two chambers 226 and 22I which are incommunication with each other through an opening 222- formed in thelower portion of the partition 2I9. The intake tube 2I6 extends into thechamber 220 and leading from the upper portion of the latter to theseptum 2I8 is a tube 223 which projects above the septum 2I8 to adjacentthe end wall 2I3 and is fitted at its upper end with a ball check valve224. Extending between the end wall 2I3 and the septum 2I8 is a cylinder225 fitted with a vertically reciprocal piston 226 carried on a suckerrod 221. The space above the septum 2I8 is divided'into two chambers 228and 229 by a partition 230 leading from diametrically opposed portionsof the cylinder 225. The upper end of the chamber 229 is closed by awall 23I and formed in the cylinder 225 are openings 232 which afford acommunication between the interior of the cylinder and thechamber 229above the piston 226. The lower end of the cylinder 225 communicateswith the chamber 22I through an opening 233 formed in the septum 2l0. Inthe operation of the invention, as depicted in Figs. 1 to 12 inclusive,to efiect a pumping action the sucker rod 28 is reciprocated as by meansof a suitable pump operating mechanism. Reciprocatlon of the sucker rod28 actuates' the piston 21 which on a down stroke operates to elevatethe mercury column D and on an up stroke to elevate the mercury columnE; the column D moving downwardly on the upstroke of the piston and thecolumnE moving downwardly on downstroke thereof. On each down stroke ofa mercury column, liquid to be pumped flows into the chamber G throughthe check valve 52, and flows through the tubes 55 and 56 into the upperportions of the chambers B and C and from which chambers the liquid isdischarged upon upstroke of the mercury columns through the outlets 62.

In event the volume of the mercury in either of the columns D and E beexcessively increased suchas to raise the level thereof to anappreciable extent, the float 46 in such increased column will moveupwardly and effect closing of the passage 43 in the sleeve valve 35 or36 -by the valve 41, as shown in Fig. So. When this occurs upwardmovement of the body of mercury below the then closed sleeve valve 35 or36 under influence of the piston 21 will cause such sleeve valve to moveupwardly and thereby uncover its associated port 39 or M such as todirect a portion of the mercury then in the space below the slide valvethrough the passage 49 or 42 into the chamber B or C and into thediminished column of mercury therein. The succeeding stroke of thepiston 21 will occasion a reduction of pressure below the then elevatedsleeve valve and will effect a consequent opening of the ball valve inopposition to the float 46, whereupon mercury in the amplified columnthereof'will flow back through the sleeve valve into the spacetherebeneath until a balance of pressures on opposite sides of thesleeve valve will be reached. thus reducing the volume of mercury in thecolumn of excessive height.

As before described the sucker rod 28 where reciprocated from a pointremote from the submerged pump is passed through a protective housing Jas shown in Fig. 5 for preventing the ingress of sand or grit to thepump packing gland 29 and the operation of which is apparent.

In the operation of the pump structure as illustrated in Fig. 13, downstroke of th piston I9I forces the body of heavy fluid I95 therebeneathdownwardly through the tube I93 into the chamber I63 thereby forcing themercury column I downwardly through the tube I11 causing the valve I19to open and thereby effecting delivery of a portion of the mercurycolumn I85 into the mercury column I81 in the chame ber I65, thuselevating the level of the mercury column I81 so as to elevate pumpedliquid previously trapped in the chamber I65. The liquidthus elevatedwill be delivered through the tube I1I past the valve I15 and throughthe upper portion of pump cylinder Y to discharge through the outletsI53. During this down stroke of the piston I9l the valves I16, I10 andI56 will open while the valves I69 will close either under the urge ofwell pressure or the suction induced by the piston I9I. This latteraction effects downward displacement of the liquid body I96 acting toelevate the liquid body I96 in the chamber I64 thus causing the thenlowered level of the mercury column I86 to move upwardly in the chamberI64; mercury from the column I88 in the chamber I66 then flowing throughth tube I18 past the then open valve I80 to replenish the column I86.The ascending levelof the column I86 on reaching the float I84 elevatesthe latter so as to efiect closing of the valve.I80 thereby inhibitingfurther flow of mercury'from the column I88 to the column I86. Thisclosure of the valve I80 is timed to occur at the moment the piston I9Ireaches its lowermost position. Lowering of the mercury column I88eifects intake of liquid being pumped through the valve I10 and tube I68and through passage I31 past valve I56.

Manifestly upstroke of the piston I9I will effect reversal of theoperation just described and in which operation the valve I19 is:closedunder the action of the float I83 at the moment the piston I9I reachesits uppermost position.

In order to effect operation of the valves I19 and I80 the floats I83and. I84 are constructed so as to be buoyant in the mercury columns andnot be influenced by the lighter bodies of fluid superimposed on themercury columns This operation of the valves I19 and I80 serves tomaintain the maximum levels of the mercury columns uniform, and preventsexcessive pumping of the bodies ofliquid I95 and I96 past the piston I9Iand whereby the piston I9I is maintained submerged in the pumping fluid.

The parts are shown as positioned. in Fig. 6 with the piston I9I as atthe termination of its upstroke and about to descend on the downstrokethereof.

In the operation of the structure depicted in Fig. 17, which constitutesa modified form of the,

structure shown in Fig. 13, movement of the pump piston efiectsdisplacement of the mercury columns I85 and I86, and theintake anddischarge of the pump liquid in. the manner described in connection withFig. 13. ,In thisinstance, however, instead of transferring mercury tomaintain the uniform level ,of the mercury columns as eifected in theconstruction of'Fig. 13 such level is maintained uniform in thestructure shown in Fig. 1'1 by transferring of .pumping fluidsuperimposed on the mercury column from one side of the pump pistonto'the other in compensating for leakagepast the piston.

In the arrangement shown in Fig. 17 the parts are shown as disposed inthe; position occupied when the piston is in its intermediate position,in which position the valves I99 are maintained open by the float I' sothat mercury is free to flow downward through either tube I11 or I18into the lower chambers I65 or I66 and also flow upwardly from either ofthe lower chambers to the upper chambers I63 or I64 according to thedirection of movement of the pump piston. Assuming that the piston ismoving downwardly, the action will then be as follows: The pumping fluidadvancing beneath the piston will force fluid in the chamber I63downwardly thereby lowering the level of the mercury column I85 in thelatter to a point where the float 20I in the chamber I63 will advancethe valve I99 connected thereto to a seated position on the'sleeve I91,which action is timed to occur at the moment the piston reaches itslowermost position. In event there has been a leakage of pumping fluidto the underside of the piston such as to create an excess of the fluidbelow the piston, such increased downward movement of the mercury columnI85 will be effected as to cause the sleeve I91 to move downward andthereby move the slide valve 201 downward therewith. When such movementof the valve 201 is suflicient to open'the port 206 to the passage205adeliver-y of a portion of the fluid inchamber I63 -to'the chamberI64 will take place, thus equalizing the fluid on opposite sides of thepiston. On the succeeding upstroke of the pump piston the level I of themercury column I will reach normal.

Manifestly, in eventjof excess pumping fluid being delivered to theupper side of the pump piston, the float '20I in the chamber- I68 willact to control the delivery of pumping liquid 7 from the. chamber I64 tothe chamber I63 through the passage 206 in a manner like that justdescribed.

It will be seen from theforeg'oin'g that I have produced a sucker rodoperated submersible double action displacement pump embodying a pair ofmercury columns constituting fluid pistons which are actuated by asingle reciprocating pump piston, and'in which the 'pump mechanism andthe associated parts are so formed and arranged as to effectivelyprevent fluids being pumped from contacting the polished surfaces of thesucker rod orofthe pump'piston and its encompassing cylinder in whichthe surfaces of the chamber containing the fluid piston may besilveredso asto prevent gritty or sticky substances from. cIinging-tQthe walls of such chamber, and in which the -pumped liquid as well asthe liquid in thewell is excluded from packing glands and otherwearingparts of the,

pump, whereby on thepump being set in operation in a wellgthe wearingparts will endure for a prolonged period of time thereby obviatingfrequent shut-downs for repairs with a con-- sequent loss of productionas is common in ordinary well pumps. 1

In the operation of the structure shown in'Fig. l9, downstroke of thepiston 226 will act to displace downwardly'the pumping fluid beneath thepiston through the port 233 and thereby cause] mercury to pass fromchamber. 229 into chamber 228 and thereby elevate the level of themercury column in the latter to effect .discharge of the liquid beingpumped throughthe tube 223 past the valve 224 and through the outlet.2M. 'On

upstroke of the piston'the pumping fluid thereabove, which is confinedbetween the piston and a packing gland 235 thereabove, will be directedin part through the passages 232 and will act to build up pressure inthe chamber .229 due to a volume of air being trapped in the upper endportion of the chamber 229. above; the liquid therein, and whichpressure will. act to assist in the followingworking downstroke ofxthepiston.

, The upstrokeof the" piston also effects intake'of thefluid beingpumped, through the tube 2l8 past valve 211 into the chamber 220 tocharge the latter in readiness for. action thereon on the pistondownstroke.

It is manifest'that in'the constructions shownv in Figs, 13, 17' and 19,the pump piston will be encompassed in a fluid body superimposed on themercury column so that the piston may be maintainedout of contact withthemercury.

By finishing the surfaces .of the pump contacted by the mercury with acoating of silver, gritty or sticky substances will be prevented fromclinging thereto. coating may be applied in any desired manner, but itis desirable that the inner faces of the mercury containing chambers belined with thin sheet copper carrying a silver plating on the exposedsurface thereof.

While I have shown and described specific em bodiments of my invention Ido not limit myself to the exact details of construction shown butmaymake such changes in the parts and their arrangement as occasion mayrequire coming within the meaning and scope of the apfording acommunication between one of said T mercury columns and the'lower end ofsaid piston, a passage affording a communication between the other ofsaid mercury columns and the upper" end of, said piston, means forreciprocating'said piston, said housing having a fluid inlet below saidmercury columnsand a fluid outlet leading from above each of saidmercury columns, and means for delivering liquid from the inlet tospaces in said housing above each of said mercury columns, said lastnamed means including, tubes leading through, said mercury columns,andcheck valves confiningthe direction of flow of'nthe liquidthroughsaid tubes .to an upwarddirection.

2.7'In a submersiblepump, a pump housing, a pair of mercury columnstherein, means for reciprocating said columns, means for delivery ofliquid being pumped above said columns, means for discharging the liquidfrom above said columns, and means vfor. maintaining a balanced relationbetween said columns.

3. In a submersible pumppalpump housing, a pair of mercurycolumnstherein, means for reciprocating, said columns,. means fordelivery of liquid being pumped above v said columns,

means for discharging the liquid from above said columns, a pair ofpassages communicating said columns, normally closed valves controllingsaid passages, and float operated means controlling opening of saidvalves to efiect transfer of mercury from one of said columns to theother.

4. In a submersible pump, a pump housing, a pair of mercury columnstherein, means for reciprocating said columns, means for delivery ofliquid being pumped above said columns, means for discharging the liquidfrom above said columns, a pair of passages communicating said columns,normally closed valves controlling said passages, said valves havingnormally open valves therein, floats in said mercury columns connectedto said last named valves for closing the latter on the mercury level ofeither ofsaid columns becoming excessive.

5. In a submersible pump, a pump housing, a reciprocal sucker rodextending into said housing from the upper end thereof, a piston on-saidsucker rod, a cylinder encompassingsaid piston, a pair of mercurycolumns in said housing, one of which extends into said cylinder abovesaid piston and the other of which extends into said cylinder below saidpiston, a pair of passages connecting said columns, normally closedvalves controlling said passages, floats in said columns, meansconnecting said floats to said valves for conditioning said valves toopen said passages under the influence of said piston, and a liquid pumpactuated by said mercury columns.

6. In a submersible pump,-a pump housing, a cylinder in said housing, apiston in said cylinder, a sucker rod connected to said piston extendingupwardly through said cylinder and above said housing, a packing glandencompassing said sucker rod, a column of mercury in saidcylinder abovesaid piston, .a pair of mercury columns in said housing one of whichconnects with the mercury column in said cylinder andlthe other of whichconnects with said cylinder below said piston, Vmeans for directingliquid being pumped into spaces in said housing above said pair ofmercury columns, means for delivering liquid fromsaid spaces, and meansfor preventing well liquid'and liquid being pumped from entering thepacking gland around'said sucker rod.

. 7.1 In a fluid piston pumping unit arranged to be lowered in' a well,a plurality of chambers provided toreceiveithe liquid to be pumped, avalved inlet and outlet in each of said chambers, a fluidinsoluble inthe liquid to be pumped in saidchambers acting as a liquid piston, areciprocating means for said fluid, a liquid provided to act on saidfluid, passageways connecting the liquid and fluid, and passagewaysconmeeting the liquid'to the reciprocating means which causes said fluidto flow in and out of said liquid chambers upon operation of thereciprocating means for said fluid; means for operating saidreciprocating means, means regulating the amount of liquid'transferredupon each reciprocation of said reciprocating means, and a meansforreplacing the liquid acting on the fluid from one chamber to another toits original amount, and a finished surface within the liquid chambersco-operating with the fluid piston to prevent gritty or stickysubstances from clinging to the walls of said chambers; means forsetting said pumping mechanism in an oil Well and means for theoperation of same. 7

8. In' a submersible pump, a pump housing having a pair of adjacentcompartments, 9, mercury column-in each of said compartments, areciprocal piston in said housing, a passage affording a communicationbetween one of said mercury columns and one end of said piston, apassage affording a communication between the other oftsaid mercurycolumns and the other end of said piston, means for reciprocating saidpiston, said housing having a fluid inlet below said-mercury columns anda fluid outlet leading from above each of said mercury columns, meansfor delivering liquid irorn the inlet to spaces in said housing aboveeach of said mercury columns, and means for maintaining the mercurycolumns at substantially constant relative volumes. V V Y 9. In asubmersible pump, a pump housing having a pair of-adjacent compartments,a-mercury column in each of said compartments, a reciprocal piston insaid housing, a passage afiording a communication between one of saidmercury columns} and one end of said piston, a passage affording acommunication between the other of said mercury columns and the otherend of said; piston, means 'forreciprocating said piston, said housinghaving a fluid inlet below said mercury columns and a fluid outletleading from above each of'said mercury columns, means for deliveringliquid from the inlet to spaces in said housing above each of saidmercury columns, and floatcontrolled means for maintaining the mercurycolumns at substantially constant relative volumes.

BENJAMIN F. SCHMIDT.

